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Which HD combination is fastest?

Tags:
  • Hard Drives
  • NAS / RAID
  • HD
  • Storage
Last response: in Storage
July 27, 2004 8:05:26 PM

I currently have two WD HDs w/ 8MB of ye olde cache, 7200 RPM.
My question concerns the fact that the HD is the bottleneck of your system.
I'm not too familiar on SATA and SCSI and RAID and whatnot, but I'm curious as to what kind of solution would give me very fast performance, HD wise, and provide me with security in terms of reliable data back up. I don't want to RAID and lose it all when one HD goes bad.

Then again, SATA might be faster.

Can I get some advice on what would help speed up my system short of trying to overclock things?
I mostly do massive file downloads/transfers, and gaming. Gaming, gaming, gaming!

Chris

More about : combination fastest

July 27, 2004 8:28:17 PM

SATA isn't faster in most cases, as todays harddrives can only write at 70ish MB/s. ATA133 / ATA100 / SATA150 all brovide more bandwidth than that. To increase performace, RAID is the only way, short of buying the small(relative to other drives) capacity W/D RAPTOR

<font color=blue><font color=red>Milk</font color=red> my <font color=red>ass</font color=red>, and call me <font color=red>Nancy</font color=red>!</font color=blue>
July 27, 2004 8:32:01 PM

It is my understanding in order to have RAID, all drives must be identical, no?!
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July 28, 2004 2:24:52 AM

After reading this I decided to put a short version in here:
No hard drive don't have to be identical.
RAID 1 should read faster than no RAID.
RAID 5 3 drives will have better performance.
RAID 5 more than 3 drives will have better performance.

IDE and SATA are identical for singel drives.

Under RAID ALL SATA controllers I've used have
better simulataneous communications
than comparably priced IDE controllers.

SCSI with a good controller card, and a comparable
configuration will have better performance.

It is NOT a requirement on most RAID controllers that all of the hard drives be identical. What is required is that the space that is used for RAID be identical on ALL hard drives.

Generally though, I have found that having ALL of the hard drives identical avoids problems. For the last several years that has been the ONLY way I have setup RAID systems.

My general practice is to setup the boot/system drive under RAID 1, and the data drives under RAID 1 or RAID 5 depending on space required. Boot/System drives are much easier to recover from in RAID 1 configurations.

On most modern RAID controllers RAID 1 will give a slight increase in transfer rate while reading data, and should provide negligible of no hit when writing data. Data is duplicated no both drives so any single drive hardware failure is recoverable.

RAID 5 requires at least 3 physical drives, and can withstand any single drive failure. Basically data is written on 2 drives and parity is written on the third rotating in some fashion what drives have data and what drives have parity. (It's usually just a round robin sort of thing but there are other factors that get involved sometimes. It still amounts to the same thing. Data packets and Parity. YES, I know some controllers allow parititioning drives to simulate multiple drives and therefore you don't need 3 drives etc..... Not really how the ORIGINAL definition was defined though.)

Since in RAID 5 you now have multiple paths that most controllers can use simultaneously to communicate with disk drives, additive cache from the drives, and reduced latency effectively multiple read/write heads you end up with increased performance.

Under RAID 5 I don't believe there is any true limit as to how many drives can be used, practical is usually between 5-8, but understand that increasing the number of drives increases the exposure to failure as only a single drive failure is recoverable.

Likely, if you are using standard 7200 RPM hard drives in a three drive RAID 5 environment a Raptor drive pair in RAID 1 will beat it by a little bit.

Keeping in mind single controller basic RAID levels ONLY give you protection from single drive errors, and there is not protection from "skeeter whoever" getting on your system and deleting files. (And this does include programs that think they are "skeeter whoever" as well.)

Backups are still a necessary event if you have important data.
July 28, 2004 6:31:52 AM

Your hard drive is NOT the bottleneck when downloading unless you're saturating a gigabit line.

hard drive > internet

When gaming your drive just loads the levels and then does nothing.

s signature has been formatted to fit your scr
July 28, 2004 5:54:08 PM

Quote:
RAID 5 3 drives will have better performance.

Than RAID1? I doubt it? Although it depends on the access pattern of course. Even with 4 drives and a decent controller RAID5 will struggle to outperform a single disk, infact, RAID10 will give better performance in workstation access patters than RAID5 with 4 drives.

Quote:
increasing the number of drives increases the exposure to failure as only a single drive failure is recoverable

Which is why large secure arrays should either have online hot spares or be RAID10 builds. A RAID10 build can theoretically loose 50% of it hard disks and remain operational and with no performance hit either :) 

<A HREF="http://www.anandtech.com/myanandtech.html?member=114979" target="_new">My PCs</A> :cool:
July 28, 2004 7:03:19 PM

I purposely ONLY stuck with the simpler RAID configurations, and what has been specifically my experience.

The initial question seemed to be only indicative of what a individual may actually install, so that is pretty much where I stayed. Additionally, since the initial question made no reference to actual configurations I didn't feel there was a need for caveats.

As with anything, Hardware, Operating Systems, Applications, usage pattern etc, can make big differences in performances.

The question though did not put many constraints on these.

Generally what I described is what I have found to be true, as well as what is considered as generally correct by RAID definition.

MOST low end controllers perform much closer to the theoretical maximums of hardware in RAID 1 configurations and RAID 0 configurations than they do in RAID 5 configurations. That performance relationship though isn't by any means indicative of what RAID 5 is capable of.

Because a specific controller or group of controllers do not implement RAID 5 as effectively as RAID 1 doesn't mean that RAID 5 is slower than RAID 1.

Currently, in my experience, the decent newer RAID cards in a RAID 5 3 drive configuration will almost always outperform RAID 1 configurations using the same hardware.

If a controller card doesn't implement RAID 5 very well then the reverse is true.

In the end though that is partly why there are different levels, implementations, of RAID. What works best in one situation may not work best in another. Things do need to be tailored to specific needs/uses.
July 30, 2004 10:04:05 PM

Simply,
HD is one of a few bottlenecks, mainly bottlenecks are PCI bus, HD, Internet, and it all depends on other weakest components too.
Raid 0+1 is the go for simple, cheap, fast, and reliable HDD setup.
For gaming get a better, bigger, faster CPU and heaps of decent quality ram, add in a top-notch graphics card and there you are.
Just don't go and mortgage the house to do it. :tongue: